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(No Model.)

H. R. GAUL. WATCH CASE SPRING.

No. 409,745. Ifageqted Aug. 27, 1889.

INVENTOR.

N. PETERS, MO-LIlMgI'lPhr, Waslinglnn, D. C.

UNITED STATES PATENT OFFICE.

HARRY R. GAUL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE KEYSTONEIVATCI-I CASE COMPANY, OF SAME PLACE.

WATCH-CASE SPRING.

SPECIFICATION forming part of Letters Patent No. 409,745, dated August27, 1889.

Application filed April 2, 1889. Serial No. 305,752. (No model.)

To aZZ whom, it may concern.-

Be it known that I, HARRY R. GAUL, of the city and county ofPhiladelphia, and State of Pennsylvania, have invented an Improvement inSprings for IVatch-Cases, of which the following is a specification.

My invention has reference to springs for watch-cases; and it consistsof certain improvements, which are fully set forth in the followingspecification, and shown in the accompanying drawings.

My object is to form a watch-case spring either the lift-spring or thecatch-spring-of sheet metal and of such form that it can be struck upout of sheet metal and then tempered and finished. By making a spring ofsheet metal not only is great cheapness in manufacture the result, but amore durable and desirable spring is formed. The spring has moreelasticity and is much lighter, and is readily secured in thewatclrcenter without screws or expensive fitting or auxiliary devices.

In carrying out my invention I stamp the springs out of sheet-steel orother spring metal, and after bending them into the proper shape to fitthe case, and so as to be adapted to act upon the lid, either to lift itor catch it, I temper the spring and then finish the exposed parts bypolishing them. The exposed parts are the lift-extension or the catch.The shape of the spring is important, as it is due to the shape that thespring is retained within the center without screws and good elasticityre sults. The part which acts upon the lid comes midway, or thereabout,of the two ends, and a part of the spring-plate is removed, so as toform a tongue, which also acts upon the lid. The end parts of the springare of a depth equal to the width of the groove in the watchease center.

The essential feature of my invention is that the spring is formed ofspring metal, and is retained within the center without the use ofscrews.

In the drawings, Figure 1 is a sectional plan of a watch-case, showingmyimproved spring applied thereto, and Fig. 2 is a cross-section of Fi 1on line a: :12. Fig. 3 is a perspective View of my improved spring as alift-spring. Fig. at is a perspective view of the spring when used as acatch-spring. Fig. 5 is a perspective View of a modification.

A are the springs.

B is the watch-ease center, and C is its internal groove.

The spring has the two body parts D D at the two extreme ends, which areunited by a thin or narrow part bounded by the slit or slits F. Theslit- E removes a part of the metal from spring action, and this formsthe narrow part F, having great elasticity, and carrying the projectingpart G, which directly acts on the lid of-the case. In Fig. 3 thisprojecting part is the lifting-projection, while in Figs. 4 and 5 it isthe catch. The spring is curved to conform to the circle of thecase-center, and the ends are curved in the opposite direction at II andare notched at I. The curvature at His to enable the ends to fit tightlyin the groove C of the center B, and the notches are to enable aninstrument to be inserted to loosen the spring when it is desired toremove it.

In the modiiicaiion shown in Fig. 5 the narrow part F, holding theprojection G, is arranged at the lower part, and the upper parts abovethe slits E are bent in at J to fit against the inner walls of thegroove of the center. The spring is held within the groove by thepressure of the bentin parts J and the ends D, and by reason of theinclination of the walls of the groove of the center, as shown in Fig.2, the narrow part F, carrying the projection G, has freedom of movementwithout binding on the lower wall of the groove of the center. In all ofthe construct-ions the two end parts or body portions are connected by anarrow port-ion, and slits are employed to produce a narrow spring part,with which the projection for acting on the lid is made integral It willbe seen that the spring is wholly supported by the case-center, and isheld in place, even against the operation of the spring, by theelasticity of the spring within the groove of the case-center.

I do. not confine myself to the mere details of construction, as theymay be modified in various ways without departing from the spirit of myinvention.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. A watch-case spring formed of stamped sheet spring metal, with freeends bent outwardly, and havinga slit or slits at its middle part tomake that of less width than the end parts and a part projecting fromsaid middle part to act on the lid. 7

2. A watch-case spring formed of stamped sheet spring metal, made curvedand having 1 a slit or slits at its middle part to make that of lesswidth than the end parts, and a part projecting from said middle part toact on the lid, and in which said end parts at their most distant edgesare curved in the opposite dif rection to the main curvature of thespring. 3

3. A watch-case spring formed of stamped sheet spring metal, made curvedand having a slit or slits at its middle part to make that I of lesswidth than the end parts, and a part projecting from said middle part toact on the lid, in which said end parts at their most distant edges arecurved in the opposite direction to the main curvature of the spring andprovided with notches for the insertion of an instrument for theirremoval.

4. A watch-case spring formed of stamped sheet spring metal, curved toconform to the curvature of the groove of the case-center and having itsends curved outwardly, and also having a portion of its middle formedwith a slit or slits and reduced in width and provided with an upwardlyand outwardly extending projection which points away from the innercurve of the spring.

5. A watch-case spring formed of stamped sheet spring metal and curvedto form a segment of a circle and (to conform to the curvature of thegroove of the case-center, and having a slit by which a portion of itsmiddle is reduced in width, and an upwardly and outwardly extendingprojection from said narrowed portion which points away from the innercurve of the spring, in combination with a watch-case center having aninner annular groove, in which the spring is received and held by itselasticity.

6 The combination of the case-center having an internal annular groovewith a spring formed like a segment of a circle and of stamped springmetal, and having its ends bent outwardly from the main curvature andshaped to tightly fit in said groove and be retained therein byfriction.

In testimony of which invention I hereunto set my hand.

. HARRY R. GAUL. Witnesses:

HARRY B. STANGER, E. O. CHAPPATTE.

